Probability

Ordering Likelihood

1

Match the Probability Word (Set A)

Draw a line from each event to the word that best describes its likelihood.

The sun will rise tomorrow
It will snow in summer in Sydney
Flipping a coin and getting heads
Rolling a 7 on a normal dice
A baby learning to walk
Certain
Even chance
Impossible
Likely
Unlikely
2

Match the Probability Word (Set B)

Draw a line to match.

You will eat food today
Finding a dinosaur at school
It will rain tomorrow
Rolling an even number on a dice
Winning the lottery
Certain
Impossible
Even chance
Possible
Very unlikely
3

Sort by Likelihood (Set A)

Sort each event.

You will breathe today
A pig will fly
Picking a red ball from 10 red balls
Flipping tails on a coin
Rolling a 6 on a dice
Impossible
Unlikely
Even chance
Likely
Certain
4

Sort by Likelihood (Set B)

Sort each event.

The moon will turn green
It raining on a cloudy day
Getting heads on a coin flip
A fish swimming in the ocean
Snow in the Sahara Desert
Impossible
Unlikely
Even chance
Likely
Certain
5

More Likely or Less Likely? (Set A)

Circle the event that is MORE likely.

Which is more likely?

Rolling an even number on a dice
Rolling a 6 on a dice

Which is more likely?

It raining in the desert
It raining in a rainforest

Which is more likely?

Picking a red marble from 8 red and 2 blue
Picking a blue marble from 8 red and 2 blue

Which is more likely?

Getting heads on 1 flip
Getting heads on all 10 flips
6

More Likely or Less Likely? (Set B)

Circle the event that is more likely.

Which is more likely?

Rolling a number less than 5 on a dice
Rolling a 6 on a dice

Which is more likely?

Picking a vowel from the word CAT
Picking a consonant from CAT

Which is more likely?

A sunny day in summer
A snowy day in summer (in Australia)
7

Impossible, Possible or Certain? (Set A)

Circle the correct answer.

You will grow taller this year

Impossible
Possible
Certain

A cat will speak English

Impossible
Possible
Certain

The next baby born will be a girl

Impossible
Possible
Certain

Tuesday will follow Monday

Impossible
Possible
Certain
8

Impossible, Possible or Certain? (Set B)

Circle the correct answer.

You will see a bird this week

Impossible
Possible
Certain

Rolling a 0 on a regular dice

Impossible
Possible
Certain

It being dark tonight

Impossible
Possible
Certain

Finding a four-leaf clover today

Impossible
Possible
Certain
9

Likelihood Scale

On a scale from 0 (impossible) to 1 (certain), where does each event fall?

Flipping heads on a fair coin

0
0.5
1

The sun rising tomorrow

0
0.5
1

Rolling a 13 on a normal dice

0
0.5
1
10

Match Probability Words to Fractions

Draw a line from each word to its approximate fraction.

Impossible
Unlikely
Even chance
Likely
Certain
1/2
0
close to 1
1
less than 1/2
11

Probability Adds to 1

The chance of something happening + not happening = 1. Find the missing part (out of 10).

10
3
?
10
?
6
10
5
?
10
?
2
10
8
?
12

Dice Probability (Set A)

A normal dice has numbers 1–6. Circle the correct answer.

Chance of rolling a 3:

Impossible
Unlikely
Possible

Chance of rolling a number less than 7:

Unlikely
Even chance
Certain

Chance of rolling a number greater than 4:

Unlikely
Even chance
Likely
13

Dice Probability (Set B)

Circle the correct answer about dice.

Chance of rolling an even number:

Unlikely
Even chance
Likely

Chance of rolling a 0:

Impossible
Unlikely
Even chance

Chance of rolling 1, 2, 3, 4, 5, or 6:

Unlikely
Likely
Certain
14

Describe the Likelihood

Describe the likelihood of each event using a probability word.

Picking a red ball from a bag of 10 red balls: ___

Getting a 6 when rolling a dice: ___

It snowing in tropical Queensland: ___

Flipping a coin and getting either heads or tails: ___

15

Sort: Equally Likely or Not

Sort each pair of outcomes.

Heads or tails on a fair coin
Rainy or sunny tomorrow
Rolling odd or even on a dice
Drawing red from 8 red and 2 blue
Picking left or right hand
Getting a 6 or not-6 on a dice
Equally likely
Not equally likely
16

Sort by Likelihood (Set C)

Sort each event.

A dog will meow
You will have a birthday this year
Picking red from a bag of 9 red and 1 blue
Getting heads on a fair coin
Rolling a number less than 2 on a dice
Impossible
Unlikely
Even chance
Likely
Certain
17

Sort by Likelihood (Set D)

Sort each event.

Tomorrow will have 25 hours
Picking a blue marble from 1 blue and 9 red
A coin landing on its edge
It being daytime at noon
Rolling an even number on a dice
Impossible
Unlikely
Even chance
Likely
Certain
18

More Likely or Less Likely? (Set C)

Circle the MORE LIKELY event.

Which is more likely?

Rolling a 1 on a dice
Rolling an even number on a dice

Which is more likely?

Picking red from 3 red and 7 blue
Picking blue from 3 red and 7 blue

Which is more likely?

Rain in winter in Melbourne
Snow in summer in Darwin

Which is more likely?

Flipping 2 heads in a row
Flipping 1 head
19

More Likely or Less Likely? (Set D)

Circle the more likely event.

Which is more likely?

Drawing a vowel from A,E,I,O,U,B
Drawing a consonant from A,E,I,O,U,B

Which is more likely?

A spinner landing on red (half red, half blue)
A spinner landing on red (mostly red)

Which is more likely?

Picking a star from 2 stars and 8 hearts
Picking a heart from 2 stars and 8 hearts
20

Probability Words (Set C)

Circle the best probability word.

A bag has 10 red marbles and 0 blue. Picking red is:

Certain
Likely
Even chance

A bag has 5 red and 5 blue. Picking red is:

Certain
Even chance
Unlikely

A bag has 1 red and 9 blue. Picking red is:

Likely
Even chance
Unlikely

A bag has 0 red and 10 blue. Picking red is:

Unlikely
Impossible
Even chance
21

Probability Words (Set D)

Circle the best word.

Rolling less than 7 on a normal dice:

Certain
Likely
Impossible

Rolling a 6 on a normal dice:

Likely
Unlikely
Impossible

Getting a number from 1 to 6 on a dice:

Certain
Likely
Even chance

Rolling a 0 on a normal dice:

Unlikely
Impossible
Even chance
22

Match Events to Likelihood (Set C)

Draw a line to match.

Picking any card from a deck
Rolling 3 sixes in a row
Picking red from all-red bag
Coin landing heads
Certain
Even chance
Unlikely
Certain
23

Match Events to Likelihood (Set D)

Draw a line to match.

A fish riding a bicycle
The moon appearing tonight
Rolling less than 4 on a dice
Drawing a specific card from 52
Impossible
Likely
Even chance
Very unlikely
24

How Many of Each Colour? (Set A)

A bag has coloured marbles. Total = partA + partB.

10
7
?
10
?
3
20
15
?
20
?
8
12
6
?
25

How Many of Each Colour? (Set B)

Find the missing number.

15
9
?
8
?
5
25
10
?
30
?
18
50
35
?
26

Describe the Likelihood (Set B)

Describe using a probability word.

A spinner with 3 equal red sections and 1 blue: landing on red is ___

Pulling a green ball from a bag of 10 green balls: ___

Rolling a number greater than 4 on a dice: ___

A cat speaking English: ___

Tossing a coin and getting either heads or tails: ___

27

Describe the Likelihood (Set C)

Use words: impossible, unlikely, even chance, likely, certain.

Picking a vowel from the word AEIOU: ___

It being dark at midnight: ___

Rolling an odd number on a dice: ___

Picking a purple marble from a bag of red marbles: ___

28

Record Dice Outcomes by Likelihood

Roll a dice 20 times. Record outcomes.

ItemTallyTotal
1
2
3
4
5
6
29

Marble Bag – Likelihood Graph

A bag has these marbles. Use the graph to answer likelihood questions.

Red
Blue
Green
1

Which colour is most likely to be picked?

2

Which colour is least likely?

3

Is picking red certain, likely, or even chance?

4

Is picking green impossible, unlikely, or even chance?

30

Spinner Sections – Likelihood Graph

A spinner has these sections. Answer likelihood questions.

Yellow
Purple
Orange
1

Is landing on yellow or purple equally likely? Why?

2

Which colour is least likely?

3

Is landing on orange impossible or just unlikely?

31

True or False? (Likelihood – Set B)

Circle TRUE or FALSE.

Impossible means it will never happen

TRUE
FALSE

Certain means it might happen

TRUE
FALSE

Even chance means both outcomes are equally likely

TRUE
FALSE

Likely means it will definitely happen

TRUE
FALSE
32

True or False? (Likelihood – Set C)

Circle TRUE or FALSE.

If a bag has 8 red and 2 blue, red is more likely

TRUE
FALSE

All outcomes on a fair dice are equally likely

TRUE
FALSE

If something is unlikely, it cannot happen

TRUE
FALSE

A spinner with equal sections gives equal chances

TRUE
FALSE
33

Likelihood Ordering – Numbers

These show probability from 0 (impossible) to 10 (certain). Continue.

2
4
6
?
?
1
3
5
7
?
34

Order Events by Likelihood (Set A)

Number these events 1 (least likely) to 5 (most likely).

?
Impossible: rolling 7 on a dice
?
Unlikely: rolling a 6 three times in a row
?
Even chance: flipping heads
?
Likely: the sun shining in summer
?
Certain: Monday follows Sunday
35

Order Events by Likelihood (Set B)

Number from 1 (least likely) to 5 (most likely).

?
It will rain fish
?
You will have a birthday this year
?
You will see a rainbow this week
?
A coin flip will land on heads
?
You will grow wings and fly
36

Write Your Own Events (Set A)

Write an event for each likelihood level.

An IMPOSSIBLE event:

An UNLIKELY event:

An event with EVEN CHANCE:

A LIKELY event:

A CERTAIN event:

37

Write Your Own Events (Set B)

Think of events from everyday life.

Something that is CERTAIN to happen at school:

Something that is UNLIKELY to happen at school:

Something with EVEN CHANCE at lunch time:

38

Likelihood in Games

Think about probability in games.

In a dice game, is rolling a 3 more or less likely than rolling an odd number? Explain.

A bag has 3 red, 5 blue and 2 green balls. Which colour are you most likely to pick? Least likely?

39

Probability from Spinners

A spinner has 4 equal sections: red, blue, green, yellow.

Chance of landing on red:

Impossible
Unlikely
Even chance

Chance of NOT landing on red:

Unlikely
Likely
Certain

Chance of landing on purple:

Impossible
Unlikely
Even chance

Chance of landing on any colour:

Unlikely
Even chance
Certain
40

Probability Reasoning

Answer these thinking questions.

Can an event be both impossible and unlikely at the same time? Explain.

If you flip a coin and get heads 5 times in a row, is the next flip more likely to be tails? Why?

A bag has 10 marbles. You want an even chance of picking red. How many red marbles should there be?

41

Challenge: Design a Fair Game

Design a game using probability.

Design a spinner game where each player has an equal chance of winning. Describe the spinner.

Now design a spinner that gives one player a better chance. How is it different?

42

Home Activity: Probability in Daily Life

Explore probability in everyday situations!

  • 1List 5 things that will happen today. Order them from least likely to most likely.
  • 2Make predictions about tomorrow's weather. Rate each as unlikely, even chance, or likely.
  • 3Put different coloured socks in a bag. Predict which colour you will pull out.
  • 4Flip a coin 20 times. Was it close to even chance (10 heads, 10 tails)?
43

Sort Events on the Likelihood Scale

Sort each event by placing it on the likelihood scale.

Rolling a 7 on a standard dice
The sun rising tomorrow
Flipping a coin and getting heads
It raining somewhere in Australia today
Drawing a red card from a standard deck
A randomly chosen month starting with J
Impossible
Unlikely
Even chance
Likely
Certain
44

Probability as a Fraction

Write each probability as a fraction.

A bag has 3 red and 7 blue marbles. P(red) = ___

A dice is rolled. P(even number) = ___

A spinner has 4 equal sections: 1 red, 1 blue, 2 green. P(green) = ___

A bag has 5 apples and 5 oranges. P(apple) = ___

45

Probability Fractions (Set A)

Circle the correct probability.

Probability of rolling a number less than 3 on a dice:

1/6
2/6
3/6

Probability of picking a vowel from the letters A, B, C, D, E:

1/5
2/5
3/5

P(impossible event) =

0
1
1/2

P(certain event) =

0
1/2
1
46

Match Events to Their Probability Description

Draw a line from each event to the correct probability word.

Drawing a blue marble when all marbles are red
Rolling any number on a dice
Flipping heads OR tails
Rolling a 6 on a dice
Certain
Unlikely but possible
Impossible
Even chance
47

Ordering Events by Likelihood

Order these events from least likely to most likely.

Events: (A) rolling a 5 on a dice, (B) picking a red card from a standard deck, (C) flipping tails on a coin, (D) picking an ace from a standard deck. Order: ___, ___, ___, ___

Explain why you ordered them this way.

48

Comparing Probabilities

Which event is more likely? Explain.

Bag A: 3 red, 7 blue. Bag B: 5 red, 5 blue. Which bag gives a higher chance of red?

Spinner A: 1/4 red. Spinner B: 3/8 red. Which spinner is more likely to land on red?

49

Complementary Events

If P(event) = p, then P(not that event) = 1 − p. Find the complement.

P(rain) = 3/5. P(no rain) = ___

P(rolling even on dice) = 1/2. P(rolling odd) = ___

P(picking green) = 1/4. P(not picking green) = ___

P(winning a game) = 0.3. P(not winning) = ___

50

Coin Flip Results

Record results of 40 coin flips in this tally chart.

ItemTallyTotal
Heads
Tails
51

Experimental Probability

A coin is flipped 100 times. Heads appeared 58 times.

Experimental probability of heads = ___/100 = ___

Theoretical probability of heads = ___

Are they the same? Why might they be different?

If you flipped the coin 1000 times, would you expect the experimental probability to be closer to 1/2? Why?

52

Probability and Sample Space

A sample space is all possible outcomes.

List all possible outcomes when rolling a dice: ___

List all possible outcomes when flipping a coin: ___

List all possible outcomes when choosing from 3 cards: A, B, C and 2 colours: red, blue: ___

53

Probability Word Problems

Solve each probability word problem.

A bag has 4 red, 2 green and 6 blue counters. You pick one without looking. What is P(green)?

A class has 18 girls and 12 boys. A student is picked at random. P(girl) = ___

What colour counter would you add to make P(red) = 1/3 if there are currently 4 red and 8 blue?

54

Challenge: Designing a Fair Game

Design a fair game using probability.

Design a spinner where each player (A, B, C) has an equal chance of winning.

Now design a spinner that gives Player A a 1/2 chance, Player B a 1/4 chance, Player C a 1/4 chance.

Is the second spinner fair? What does 'fair' mean in probability?